The focal length of a macro lens is important because, the shorter it is, the closer the subject must be to reach full 1:1 magnifi cation. This can lead to the subject being shaded by the lens barrel, and can also potentially scare living creatures away. A longer macro focal length, such as the 150mm, is therefore preferred by many nature-inclined macro photographers as it allows them to shoot further away from their subject. Obviously, the extended focal length of the Sigma 150mm f/2.8 has limited appeal as a portrait lens, unlike many macro lenses in the 80-100mm range. Still, if you’re after a lens for critical macro photography, then Sigma’s 150mm f/2.8 is hard to beat.

Released in 2011, the Sigma 150mm f/2.8 EX DG OS HSM updates the older non-OS model that came out in 2004 with the addition of Sigma’s bespoke Optical Stabilisation (OS) technology. This provides three settings via a switch on the left-hand side of the lens: ‘Mode 1’ for for full stabilisation; ‘Mode 2’ for verticalonly stabilisation and ‘Off’ for when the lens is mounted on a tripod. Used at distance, Sigma claims the technology provides up to four stops of compensation, although this will, of course, decrease the closer the lens is to its subject. It’s worth noting that while the lens is available for Nikon, Canon and Sony A-mount cameras, the Sony version does not come with optical stabilisation.

Internally, the Sigma 150mm is constructed of 19 elements in 13 groups, which includes three Special Low Dispersion (SLD) elements. In addition, both the front and rear elements feature a Super Multi- Layer Coating to reduce fl are and ghosting. Maximum aperture is f/2.8 with a minimum of f/22, although the effective aperture varies according to the focal distance, reducing the aperture by as much as two stops at the maximum 1:1 magnifi cation to give an f/5.6-f/45 range. Focusing is internal and uses a Hyper Sonic Motor (HSM) for fast and quiet operation.

At 150mm in length and over 1kg in weight, the Sigma 150mm f/2.8 is big and heavy. Thankfully, it does come supplied with a removable tripod collar. In terms of build quality the lens has a smooth matt black fi nish, which gives it a premium feel. The focus ring is positioned at the front of the lens and offers a smooth action with a good amount of resistance to allow for accurate adjustments. A focus window is located just behind this and supplies distance measurements in feet and metres as well as the magnifi cation ratio. A focus distance limiter switch can be used to restrict focus to either 38-53cm or to 53cm-infi nity for faster focusing. Another switch provides AF/MF options, although manual override is always available even when the host camera’s autofocus module is enabled.

Sharpness peaks between f/8 and f/16, with only a small loss of critical sharpness at f/2.8. At the other extreme, sharpness does drop more noticeably beyond f/16.

Specs

Construction 19 elements in 13 groups

Minimum focus distance 38cm

Aperture range f/2.8-f/22

Filter size 72mm

Dimensions 150mm x 79.6mm

Weight 1,150g

Verdict

Although not quite as versatile as an 85mm or 105mm macro for portraiture, the Sigma 150mm f/2.8 excels. While optical stabilisation makes handheld shooting close-up possible, its not inconsiderable weight makes it much better suited to tripod use, where it really excels. Better still, the price of the Sigma 150mm f/2.8 has fallen by around £350 in the years since its release.